Statistical Methods For Regional Resource Appraisal

The paper identifies the major components of price change which affect the determination of the internal rate of return of a mining project. It illustrates several price indexes which may be used to measure general price increases, identifying techniques which might incorporate them into mine valuation procedures. The "hurdle rate" for new investment is discussed.

This paper is an attempt to outline the present status of underground mining contracting in Canada, and to present certain facts concerning the writing and administration of underground mining^ contracts which, hopefully, may be useful to those intending to engage a mining contractor. The paper is based on the author's experience as a contractor and also as a consulting engineer advising others in the purchase of contractors' services.

A new electromagnetic depth sounding technique was applied to the -measurement of salt thickness above the workings in the Central Canada Potash Mine at Colonsay, Saskatchewan. The initial tests indicate that this new technique can measure salt thickness and that the technique possesses operational features which make it possible to monitor trends in salt thickness throughout the mine. The technique can be applied using existing equipment, but the tests do indicate the desirability of...

Attention is drawn to the ventilation problems arising from the use of diesel vehicles underground, especially in view of the fact that diesel fumes in combination with other pollutants may be more harmful than diesel fumes alone or the other pollutants alone.Means for minimizing the harmful effects of using diesels underground are listed, and the quantities of air required in mines in which diesel-powered vehicles are used are discussed. Mines are classified in three categories on the basis...

Should oil and gas be proven in commercial quantities on the Labrador Shelf, current technology is not adequate for production operations in this severe environment, which includes yearly invasion of pack ice and icebergs. The fishery of this section of the North Atlantic is a vital resource to which a major oil spill or blow-out would impose an intolerable burden. This means that production systems must be designed and built to be fail-safe.The experiences of mining in Bell Island and Cape...

Wear of six types of grinding balls was compared with, and without corrosion inhibition in grinding Ni-Cu sulphide and hematite ores in laboratory ball mills. Forged steel balls (R,. 60 to 65) and three types of white cast iron balls (R<. 50 to 65) were susceptible to corrosive wear and two types of stainless steel balls [AISI Type 440C (Rc 65) and AISI Type 302 (Rc 35)} were relatively immune. The relative wear rates of the five types of hard balls (R, 50 to 65) were dependent on the...

A number of plant-scale cyanidation tests were carried out in an attempt to uncover the causes of fluctuations in gold recovery efficiency. Computer analysis of the results verified that the treatment of reclaimed waste rock material along with normal run-of-mine ore was having an adverse effect on metallurgical efficiency. Mineralogical examinations showed that the free gold particles in the dump material were heavily tarnished or coated (predominantly by hydrated iron oxide), accounting for...

The fact that there are standard units of mass, distance and time is taken for granted. It is also accepted that the type of instrument used to measure one of these parameters is irrelevant to the way the measurement is reported. Some geophysical parameters, for example magnetic field strength and gravity, have generally accepted units, the gamma and milligal, which are defined in SI terms. These units are used irrespective of the equipment used to -measure them. By contrast, the situation...